CN115461274B

CN115461274B - Gripping system and method for inserting separator sheets in a container

Info

Publication number: CN115461274B
Application number: CN202180031192.0A
Authority: CN
Inventors: C·斯坦纳
Original assignee: Bobst Mex SA
Current assignee: Bobst Mex SA
Priority date: 2020-03-18
Filing date: 2021-03-18
Publication date: 2024-06-28
Anticipated expiration: 2041-03-18
Also published as: BR112022018412A2; EP4121355B1; US20230182936A1; EP4121355A1; JP2023517702A; KR20220153633A; CA3175163A1; WO2021185994A1; CN115461274A; BR112022018412B1

Abstract

The invention relates to a gripping system comprising a gripping head (15), the gripping head (15) being intended for a sheet transport device, in particular for transporting inserted sheets between rows of folding boxes inserted into a container, the gripping head (15) having at least one support frame (80) and a plurality of suction elements. The suction element is mounted on a holding element (50) housed on a support frame (80) so as to be displaceable with respect to the support frame (80).

Description

Gripping system and method for inserting separator sheets in a container

Technical Field

The present invention relates to a gripping system for gripping, transporting and inserting an inserted sheet between rows of folding boxes in a container. Such a gripping system may be used with a folder gluer.

Background

The folding and gluing machine glues and folds flat folding boxes that will contain products such as blister packs for pharmaceutical or other products (e.g. products packaged in the food or pharmaceutical industry). A plurality of flat folded boxes can then be effectively stored in a container (also referred to as a container) for delivery to a manufacturer.

Document CH 659627 describes an example of a device for filling a folding box from a folding-gluing machine to a container. The folded boxes are transported to the containers by a box conveyor at the end of the folding and gluing machine. Each container may hold a large number of folded boxes, for example tens or hundreds of boxes.

In order to form separate and stable rows of folded boxes in the container, an insertion process is required. The insertion process includes disposing the inserted sheet material in an empty container to form a barrier between the rows of folded boxes. This operation of inserting the insert sheet is necessary to prevent the cartridges from crossing, for example, during transportation of the filled containers.

The insert sheet is typically a sheet of corrugated and cut paperboard, typically for the purpose of prefabricating three parallel fold lines. The fold lines enable the insert sheet to form a "V" when folded at the fold lines. The flaps are located on each side of three parallel fold lines.

When the two lateral flaps of the insert sheet are brought towards each other, the insert sheet has a three-dimensional shape with flat folds (folds) substantially perpendicular to the flaps. The dimensions of the tab correspond to the dimensions of the bottom of the container such that when the folded insert sheet is placed in the container, the flat folds are positioned vertically.

In production, workers are typically assigned to manually insert vertical inserts between two rows of cassettes. The cassettes are then arranged on either side of the vertical insert sheet.

A sheet conveying apparatus having a gripping head is known from document WO2017/202500 A1. For inserting the sheet between the rows of folding boxes in the container in the downstream portion of the folder gluer.

WO2017/202500A1 discloses a machine and method for automatically grabbing, folding and inserting folded insert sheets into containers. The machine has a gripping head that grips the insertion sheet, and a driver that moves the gripping head from a position where the insertion sheet is gripped to a position where the insertion sheet is to be placed. The machine is briefly described below with reference to fig. 1 to 9.

Fig. 1 shows a general view of the elements of a station 1 for filling folded boxes 3 into containers 2 (also called containers), the station 1 possibly being placed at the outlet of a folder gluer.

The folding box 3 may be prepared by a folding-gluing machine that glues and folds the folding box 3 flat, and then the folding box 3 may be piled up in a folded and glued state with a reduced footprint in the container 2 for easy transportation. The term "folding carton" herein refers to a folding carton that is folded flat to be disposed in the container 2.

The container 2 may be, for example, a box in the form of a parallelepiped, capable of holding a plurality of folded boxes 3. For example, the container 2 is made of cardboard. A container 2 filled with two rows of folded boxes 3 on the rim is shown as an example in fig. 2.

At the filling station 1, as can be seen for example in fig. 1, the conveyor 5 of containers conveys empty containers 2 to a filling zone B in which the containers 2 are loaded with folded boxes 3. Once loaded, the containers 2 move from the loading zone B onto the emptying zone Lc (arrow Tb). The loaded containers 2 are then emptied to an outlet along the emptying section Lc, and the containers 2 are transported to the filling zone B, but in the opposite direction. The loaded containers 2 are emptied outside the conveyor 5 (arrow Ld)

The container 2b can perform a new loading cycle by being reintroduced at the beginning of the transport to perform a new loading of the second layer of cassettes (arrow Te). The container 2b has a capacity and thus a greater height to allow access to the second layer box (see fig. 2a and 3 c).

The cassette conveyor-loader 4 is designed to grasp a folded cassette 3, for example, arranged in sheets at the outlet of the folder gluer, and to transfer the folded cassette 3 to the loading zone B. The folded boxes 3 with a substantially arcuate path are orderly arranged in the containers 2 by means of the movable end 6 of the box conveyor-loader 4. Thus, the folded boxes 3 are generally arranged in at least two rows of folded boxes 3 (fig. 3 a) side by side, vertically aligned with each other and separated by the folded insert sheet 11 a.

The insert sheet 11a is, for example, a piece of cardboard which is folded to preform at least three fold lines L1, L2, L3 (see fig. 4a and 4 b). The fold lines L1, L2, L3 are parallel to each other. Once folded, the insert sheet 11a has a flat fold 12 perpendicular to the flat base formed by the two lateral flaps 13a, 13b of the insert sheet 11a placed against each other by folding (fig. 4 b). The insert sheet 11a is dimensioned such that, once folded, the flat base has dimensions complementary to those of the bottom surface 14 of the container 2 (fig. 3a, 3 b). The fold lines L1, L2, L3 are for example centred such that the flat fold 12 is centred and then the folded insert sheet 11a placed on its base will have an inverted T-shape in cross section.

The filling station 1 comprises an insertion device 10 enabling gripping of the insertion sheet 11 from the stack, folding of the insertion sheet 11 along the folding lines L1, L2 and L3, and then arranging the folded insertion sheet 11 in the empty container 2 before the empty container 2 is filled with the folding box 3. These operations, also known as "insertion", make it possible to separate and retain the folded boxes 3 in the container 2 in at least two stable rows.

To this end, the insertion device 10 comprises a gripping head 15 and a drive means 16, the drive means 16 being designed to move the gripping head 15 at least along a vertical movement (for example a straight line) and a horizontal movement (for example another straight line).

The insertion device 10 likewise comprises a conveyor belt 5 enabling successive packets of inserts to be brought up so as to ensure an insertion operation that does not stop. When the last insert of a packet is grasped and inserted into a container, the conveyor belt 5 advances and brings the next insert packet.

As best shown in fig. 6, the gripping head 15 comprises at least one first suction element 17a, 17b, at least one second suction element 18a, 18b, at least one linear element 19a, 19b (at least the first suction element 17a, 17b is mounted on the at least one linear element 19a, 19b and is capable of moving the at least one linear element 19a, 19b by sliding the at least first suction element 17a, 17 b), and a controllable actuation mechanism 20.

In the example shown in fig. 6, 7a, 7b, 8a, 8b and 9, the gripping head 15 comprises two first suction elements 17a, 17b, two second suction elements 18a, 18b and two linear elements 19a, 19b. One of the first suction elements 17a and one of the second suction elements 18a are mounted to slide on the first linear element 19 a. The other of the first suction elements 17b and the other of the second suction elements 18b are mounted to slide on the second linear element 19b.

The suction elements 17a, 17b, 18a, 18b are designed to grasp the insert sheet 11. They comprise respective support members 23, for example in the form of brackets, at the lower end of which support members 23 suction openings are arranged. These suction openings lie in a horizontal plane.

The suction opening is connected to a vacuum source, for example by means of a flexible hose and at least one valve. A valve, for example a controllable valve, may be located between the vacuum source and the flexible hose and may be controlled by the control unit 30 to establish or shut off a low pressure in the suction opening. Thus, when vacuum is delivered to the suction opening, the insertion sheet 11 can be grasped by suction.

The suction elements 17a, 17b, 18a, 18b may likewise comprise suction cups arranged in the region of the suction openings in order to facilitate gripping of the insert sheet 11 by improving the tightness between the insert sheet 11 and the suction openings.

At least the first suction elements 17a, 17b can be displaced by sliding on the linear elements 19a, 19b by the actuation mechanism 20 between a gripping position (fig. 7a, 8a and 6) and a folded position (fig. 7b, 8b and 9).

In the gripping position (fig. 7a, 8a and 6), the first suction elements 17a, 17b and the second suction elements 18a, 18b are positioned spaced apart from one another. This position allows the suction elements 17a, 17b, 18a, 18b to be able to grasp the lying insert sheet 11 by the suction side flaps 13a, 13 b.

In the folded position (fig. 7b, 8b and 9), the first suction elements 17a, 17b and the second suction elements 18a, 18b are closer together than in the gripping position. This closer proximity of the suction elements 17a, 17b, 18a, 18b allows folding of the insert sheet 11. In particular, gaps are designed between the supports 23 of the suction elements 17a, 17b, 18a, 18b, to avoid wedging in the central flat fold 12 (figures 8b and 9).

The two first suction elements 17a, 17b are joined together by a first support bar 21 and the two second suction elements 18a, 18b are joined together by a second support bar 22. The support bars 21, 22 make it possible to ensure good stability of the suction elements 17a, 17b, 18a, 18b and good planarity of the suction openings. Tubing may be designed in the support rods 21, 22 to connect the suction openings to each other and to a common connection 24 of each rod 21, 22, to which common connection 24 a flexible hose connected to the pump may be connected.

The actuating mechanism 20 is designed to displace the second suction elements 18a, 18b equally by sliding over the linear elements 19a, 19b between the gripping position and the folded position. The actuation mechanism 20 is designed to allow a synchronous displacement of the support rods 21, 22 towards each other with the same amplitude, which enables folding of the insert sheet 11 with the central flat fold 12.

The linear elements 19a, 19b on which the suction elements 17a, 17b are mounted to slide comprise, for example, each a cylindrical rod. For example, complementary cylindrical holes are designed in the uprights of the support 23 of the suction elements 17a, 17b, 18a, 18 b. The actuation mechanism 20 includes a controllable actuator 25 and a linkage system.

The linkage system comprises a vertically movable transverse shaft 26 connected to a controllable actuator 25 and at least one linkage 27 (in this example four linkages 27).

A first end of the link 27 is pivotably connected to the transverse shaft 26 and a second end of the link 27 is pivotably connected to the suction elements 17a, 17b, 18a, 18b.

In this example, each suction element 17a, 17b, 18a, 18b is connected by a respective connecting rod 27 to a transverse shaft 26, the transverse shaft 26 passing through a cylindrical opening of a first end of the connecting rod 27. The second end of the link 27 is pivotally mounted on the support 23, for example by means of a pivot.

The links 27 are preferably all of the same size, which enables synchronous displacement of the support rods 21, 22 toward or away from each other with the same amplitude.

In operation, lowering of the transverse shaft 26 tilts the linkage 27 towards the horizontal, moving the first suction elements 17a, 17b away from the second suction elements 18a, 18b. On the other hand, the elevation of the transverse shaft 26 straightens the links 27, closing the V-shaped opening between the links 27, which brings the first suction elements 17a, 17b closer to the second suction elements 18a, 18b.

The controllable actuator 25 comprises an electric motor. The actuating mechanism 20 comprises a screw 28, for example designed to be driven in rotation by an electric motor, the screw 28 being inserted perpendicularly into the thread of the transverse shaft 26, the screw 28 being perpendicular to the latter. The screw 28 is, for example, a ball screw. The balls interposed between the screw 28 and the transverse shaft 26 ensure a rolling function, which allows limiting friction and achieving a fast movement.

Rotation in a first direction of the motor drives the raising of the transverse shaft 26 (fig. 7 b) and rotation in the opposite direction drives the lowering of the transverse shaft 26 (fig. 7 a). The actuation mechanism 20 further includes at least one guide groove (or slot) 29 designed to cooperate with one end of the transverse shaft 26 to guide the vertical displacement of the transverse shaft 26. The two guide grooves 29 may thus cooperate with one respective end of the transverse shaft 26.

The insertion device 10 further comprises a control unit 30, such as a computer, a control unit or a micro control unit, comprising a memory and a program enabling execution of a series of instructions enabling in particular control of the driving means 16 and/or the actuation mechanism 20 and/or generation of a vacuum in the first and second suction elements 17a, 17b, 18a, 18b.

The driving device 16 includes a linear guide rail 31 horizontally fixed to the frame and a carriage 32 slidable along the linear guide rail 31. The linear guide 31 is, for example, a rail, a rack, or a belt. The drive means 16 likewise comprise an arm 33 extending in the vertical direction, at the end of which arm 33 a gripping head 15 is attached. The arm 33 is vertically movable in a base carried by the carriage 32.

The controllable motor of the drive device 16 is designed to displace the carriage 32 along the linear guide 31 and to displace the arm 33 vertically in the base. The drive means 16 thus allow on the one hand to control the vertical displacement of the gripping head 15 above the workstation to lower and grip the insert sheet 11 and lift the insert sheet 11 back upwards, and on the other hand to lower the insert sheet 11 into the container 2 above the insertion zone E and to raise again the gripping head 15 from which the insert sheet 11 has been unloaded. Likewise, the drive means 16 enable a linear horizontal displacement to be controlled, allowing the insertion sheet 11 to be transported from the workstation to the insertion zone E, and the gripping head 15 to be returned from the insertion zone E to the workstation for gripping a new insertion sheet 11.

A conveyor 34 may be provided at the workstation to continuously convey the stack of inserted sheets 11 (fig. 5).

Fig. 5, in combination with fig. 8a, 8b and 9, shows the different steps of a method of grabbing, folding and loading an inserted sheet 100 by the insertion device 10.

The control unit 30 controls the drive means 16 to position the gripping head 15 above the inserted sheet 11 lying at the workstation, the first and second suction elements 17a, 17b, 18a, 18b being positioned away from each other in the gripping position. Next, the control unit 30 commands the creation of a vacuum in the first and second suction elements 17a, 17b, 18a, 18b to grasp the insertion sheet 11, the grasping position allowing grasping of the insertion sheet 11 by suction in the area of the side flaps 13a, 13 b.

Next, the control unit 30 controls the controllable displacement device with a linear vertical displacement to raise the gripping head 15, and then with a linear horizontal displacement to guide it to the insertion zone E, where the hollow, open containers 2 have been transported by the conveyor belt 5 of the containers. Then, the control unit 30 commands the motor to rotate to raise the transversal shaft 26 (fig. 7 b) and thus straighten the connecting rod 27. The first and second suction elements 17a, 17b, 18a, 18b slide towards each other on the linear elements 19a, 19b bringing the first suction elements 17a, 17b and the second suction elements 18a, 18b closer together, which enables folding of the inserted sheet 11 that has been gripped (fig. 9).

This folding may be done in flight, i.e. during the transport of the insert sheet 11 to the insertion zone E, in particular during the horizontal displacement of the gripping head 15. The control unit 30 then instructs the drive means 16 to vertically lower the gripping head 15 into the container 2.

Vacuum is maintained in the suction elements 17a, 17b, 18a, 18b until the head 15 has placed the insert sheet 11 on the bottom of the container 2. The control unit 30 then instructs the vacuum to be stopped to release the insertion sheet 11. The insert sheet 11 is kept in a folded state in the container 2, wherein the flat crease 12 is kept vertical by the cooperation of the bottom surface 14 and the side flaps 13a, 13b (fig. 3 b).

The control unit 30 then commands the raising of the gripping head 15 and controls the motor to rotate in the opposite direction to lower the transverse shaft 26, the lowering of the transverse shaft 26 being guided by the guide groove 29. Lowering of the transverse shaft 26 tilts the connecting rod 27 in a horizontal direction, thereby moving the first suction elements 17a, 17b away from the second suction elements 18a, 18b.

Such control in the gripping position can be achieved during vertical lifting or transport of the gripping head 15.

The containers 2 containing the folded insert sheets 11 may then be transported by the conveyor belt 5 of the containers along the transport section La to a loading zone B, where the containers 2 may receive folded boxes 3 that have been transported by the box transporting-loading machine 4.

Disclosure of Invention

The object of the present invention is to further improve the machine disclosed in WO2017/202500A1 to obtain a more precise and safer control of the vertical movement of the gripping head. This object is solved by a gripping system according to the invention and a method of introducing an insert sheet according to the invention.

According to a first aspect, the invention relates to a gripping system for placing an insert sheet between rows of folded boxes in a container, the gripping system comprising a gripping head configured to grip and pick up the insert sheet from a loading position, displace and position the insert sheet on a storage surface in the container.

The gripping head has a support frame and a plurality of gripping elements configured to adhere to an upper surface of the insertion sheet, the gripping elements being connected to the support frame via a plurality of holding elements movably mounted to the support frame, and wherein the holding elements and the gripping elements are movable in a vertical direction relative to the support frame when the gripping elements contact a storage surface in the insertion sheet or container, wherein the gripping system further comprises a control unit and a sensing device configured to sense a vertical displacement of the holding elements relative to the support frame, wherein the control unit is configured to receive information from the sensing device and to determine when the gripping head is in contact with the insertion sheet or the storage surface.

The vertical direction may be defined as a direction perpendicular to the top surface of the insert sheet, i.e., a normal direction of the insert sheet. The vertical direction may coincide with the direction of gravity. Thus, the horizontal direction may be defined by the plane of the surface of the insert sheet. In addition, the horizontal direction may be defined as 90 ° with respect to the vertical direction.

The invention is based on the recognition that the contact of the gripping element with the insert sheet can be adjusted to ensure that the insert sheet is stored at the correct height while limiting the impact and potential damage to the insert sheet and the row of folding boxes. The movable gripping and holding elements thus enable the gripping head to yield and store the inserted sheet at the correct height and to contact the folded boxes in the container and to yield when the gripping elements contact a row of folded boxes in the container. The storage surface may be the upper surface of a row of folded boxes or the bottom surface in a container.

In one embodiment, the control unit is further configured to stop further vertical downward movement of the gripping head when the sensing means senses vertical movement of the at least one holding element.

In one embodiment, the holding element is a rod which is accommodated in an opening in the support frame, and wherein the rod comprises a free end on which the clamping element is attached. The opening may be a guide opening for the rod. Thus, the vertical displacement may be an axial displacement of the holding element in the longitudinal extension direction.

The clamping element may be biased away from the support frame by a biasing member. A biasing member may be mounted around each rod and suspended between a first abutment surface located on the support frame and a second abutment surface located on the retaining element. Alternatively, the biasing member is a pneumatic cylinder or a gas cylinder. The pneumatic cylinder may be mounted within the leg. The biasing member ensures that the gripping element is always in a precisely defined position when not in contact with the inserted sheet.

The control unit of the gripping system may be configured for controlling the displacement of the gripping head and for operating the gripping elements in an alternating manner between a gripping state and a release state such that the gripping elements are in a gripping state when the gripping head contacts an inserted sheet in the loading position and in a release state when the gripping head subsequently contacts the storage surface with an inserted sheet.

In one embodiment, the gripping system further comprises a memory comprising spatial coordinates of a first lowering position of the gripping head and spatial coordinates of a second lowering position defining a starting point of the first and second vertical lowering trajectories, wherein the first lowering trajectory is vertically aligned with the loading position and the second lowering trajectory is vertically aligned with the storage position, wherein the control unit is configured to operate the gripping head to move it to the first and second lowering positions, respectively.

The endpoints of the first and second vertical drop trajectories may be defined by a first vertical end position and a second vertical end position, wherein the first and second vertical end positions are defined solely by the sensing device.

In one embodiment, the gripping system comprises a linear guide, wherein the gripping head is linearly moved and guided by the linear guide in a lateral direction, wherein the lowered position is defined as one-dimensional coordinates in a horizontal plane along the longitudinal extension direction of the linear guide.

In one embodiment, the sensing device comprises at least one position sensor on the support frame and at least one detection element on the at least one holding element, wherein the position sensor is configured to sense a displacement of the detection element.

For a simple system, a sensor may be used to retrieve a representative value of the displacement of the holding element. Alternatively, in another embodiment, sensing means may be provided for more than one holding element if additional measurement accuracy is required.

The sensor may be a magnetic sensor or an inductive sensor and the detection element may comprise a metallic material. The detection element may be a mechanical stop mounted on the holding element, and wherein the mechanical stop is configured to limit downward movement of the holding element relative to the frame. The mechanical stop may be a separate annular member mounted around the rod. Thus, the sensor may be a position sensor, as it is configured to detect a change in position of the detection element.

In one embodiment, the sensing device comprises a force sensor configured to detect a contact pressure between the gripping element and a contact surface on the insertion sheet. This enables setting of different thresholds of contact pressure, below which the clamping element should be in a clamped state/configuration and a released state/configuration.

In another embodiment, at least one of the holding elements may comprise at least one optically readable reference point, wherein the position detector is an optical sensor.

In another embodiment, the sensing device may comprise an electromechanical sensing switch comprising a mechanical latch configured to be activated at a predetermined displacement distance of the clamping element, wherein the control unit is configured to activate and deactivate the clamping element in response to activation of the electromechanical switch.

This typically works by initial activation of a switch when the gripping head contacts the inserted sheet, so that the gripping element grips the sheet (e.g. the vacuum chuck is activated). The gripping elements then contact the surfaces of the rows of folded boxes located in the container, and the gripping elements are deactivated so that the inserted sheet is released. Thus, the electromechanical switch may be used in an alternating manner such that the clamping element is activated and deactivated.

In one embodiment, the support frame comprises a first frame portion comprising a first set of clamping elements and a second portion comprising a second set of clamping elements,

Wherein the first and second frame portions are movable relative to each other between a distal position in which the first and second sets of clamping elements are positioned away from each other and a proximal position in which the clamping elements are positioned closer to each other than in the distal position such that the first and second sets of clamping elements are horizontally displaceable relative to each other. This provides for horizontal displacement and spacing of the gripping elements and thus movement of the folded insert sheet.

In one embodiment, the gripping element may be a suction element configured to apply suction to the inserted sheet. The holding element may be provided with an internal conduit connected to the suction element, wherein the vacuum line is connected to the end of the rod opposite to the suction element.

In one embodiment, the control unit is configured to apply a vacuum to the gripping head when the sensor detects a displacement of the holding element relative to the support frame and when the control unit determines that the gripping head is in the loading position.

In addition, the gripping element may be further configured to vent air to apply positive pressure to the inserted sheet when the control unit determines that the gripping head is in contact with the storage surface.

The control unit may be configured to stop the downward movement of the gripping head when the sensing means detects a vertical displacement of the holding element relative to the support frame.

Preferably, the control unit is configured to gradually stop/slow down the downward movement of the gripping head when the sensing means detects a vertical displacement of the holding element with respect to the support frame.

According to a second aspect, the present invention relates to a method of introducing an inserted sheet into a container or between rows of folding boxes by using a gripping head comprising a plurality of gripping elements mounted on a vertically displaceable holding element movably connected to a support frame, the method comprising the steps of:

moving the gripping head into vertical alignment with the loading position, lowering the gripping head so that the gripping element contacts the upper surface of the inserted sheet,

Moving the support frame portion further downwards a predetermined distance, whereby the support frame is moved relative to the holding element and the clamping element is held stationary against the upper surface of the insert sheet,

Detecting a displacement of the at least one holding element and stopping a further downward movement of the gripping head,

Grasping the insert sheet such that the insert sheet adheres to the gripping element,

Pick up, displace and position the insert sheet such that the insert sheet is aligned with the opening in the container,

Lowering the gripping head and placing the insert sheet on a storage surface in the container,

Further moving the support frame part downwards towards the predetermined distance, whereby the support frame is moved relative to the holding element and at the same time the insert sheet remains stationary against the upper surface of the insert sheet,

-Detecting the displacement of the at least one holding element and stopping the further downward movement of the gripping head, and

-Releasing the gripping element from the insertion sheet.

The gripping of the insert sheet may advantageously be performed by suction.

In one embodiment, the method may further comprise the steps of:

-detecting the vertical displacement of the holding element with a sensor; and

Stopping the vertical movement of the gripping head.

Drawings

The invention will now be described by way of example and with reference to the embodiments shown in the drawings in which like reference numerals will be used for similar elements and in which:

fig. 1 shows elements of a filling station, in particular a cassette conveyor/filling machine, a container conveyor belt and an insertion device according to the prior art;

FIG. 2a shows an example of a container with side walls shown transparent loaded with folded inserts interposed between two rows of boxes in an orderly arrangement;

FIG. 2b shows another example of a container whose side walls are shown as transparent, the container being loaded with folded boxes arranged in an orderly fashion with a folded insert sheet interposed between two rows of boxes, and having two layers of folded boxes, the folded insert sheet being interposed between the two layers;

Figures 3a and 3c show cross-sectional views of the container, folding box and insert of figures 2a and 2 b;

FIG. 3b shows a view similar to FIG. 3a with the folding box removed;

FIG. 4a shows a top view of an insert sheet prior to folding;

FIG. 4b shows a perspective view of the insert sheet of FIG. 4a during the folding process;

FIG. 5 shows a perspective view of the insertion device of FIG. 1;

Fig. 6 shows a perspective view of the gripping head of the insertion device of fig. 5, wherein the cover element is shown transparent and the suction element is shown in the gripping position;

FIG. 7a shows a view of the gripping head of FIG. 6 with the cover element removed to better show the actuation mechanism;

Fig. 7b shows a view similar to fig. 7a, with the suction element in a folded position;

fig. 8a shows a side view of the gripping head of fig. 7 a;

Fig. 8b shows a side view of the gripping head of fig. 7 b;

fig. 9 shows a perspective view of the gripping head of fig. 7b, wherein the gripping head has been pivoted 180 ° and carries a folded insert sheet;

FIG. 10 shows a perspective view of a gripping head according to one embodiment of the invention;

fig. 11 shows a side view of the gripping head of fig. 10 in a state in which it is lowered onto an insert sheet;

Fig. 12 shows a side view of the gripping head of fig. 10 in a state in which it is placed on an insert sheet;

fig. 13 is a perspective view showing the insertion head of fig. 12 in a state in which an insertion sheet is grasped;

fig. 14 shows a perspective view of the insertion head of fig. 13 in a state in which the insertion sheet is being transported; and

Fig. 15 shows a perspective view of a gripping system according to the invention.

Detailed Description

Embodiments of the present invention will now be described with reference to fig. 10 to 15. For those elements known from fig. 1 to 9, the same reference numerals are used, and only differences in construction and operation between the prior art gripping head and the gripping head as shown in fig. 10 to 14 will be discussed below.

The main difference between the prior art gripping system and the gripping system 15' of fig. 10 to 14 is that the gripping elements 17, 18 of the gripping head 15 according to the invention are mounted to the gripping head 15 so as to be displaceable relative to the support bars 21, 22 of the support frame 80. In particular, the gripping elements 17, 18 are mounted so as to be displaceable in a direction parallel to the vertical direction, moved by the driving device 16 when the gripping head 15 is lowered to pick up or store the inserted sheet 11.

In the embodiment shown in the figures, the clamping elements 17, 18 are mounted at the lower end of the holding element 50, where the holding element 50 is formed as a rod. The lower end of the holding element 50 is configured as a free end on which the clamping elements 17, 18 are mounted. The holding element 50 is movably accommodated in the support bar 21, 22. In the example shown, and as best seen in fig. 13, the retaining element 50 is received within an opening 52 provided in the support bar 21, 22. The clamping elements 17, 18 are displaceable in a direction defined by the axial extension of the holding element 50.

A stopper 54 is provided at the upper end of the holding member 50. The stopper 54 restricts downward movement of the holding member 50 with respect to the support rods 21, 22 by abutting the upper surfaces of the support rods 21, 22.

A biasing means 56 is provided below the support bars 21, 22 of the support frame 80 (and thus between the support bars and the clamping elements 17, 18), the biasing means 56 biasing the clamping elements 17, 18 away from the support bars 21, 22. In the embodiment shown, the biasing means 56 is formed as a compression spring 56 mounted around the rod-like holding element 50. As best shown in fig. 14, the compression spring 56 is suspended between a first abutment surface 57 on the support frame 80 and a second abutment surface 59 on the retaining element 50.

As shown, the clamping elements 17, 18 are preferably configured as suction elements 17, 18. The suction elements 17, 18 are connected to a vacuum generator (not shown). However, other types of mechanical clamping elements are also possible. For applying vacuum to the suction elements 17, 18, a vacuum connection 60 is provided at the gripping head 15. The vacuum connection 60 is connected via a vacuum line 62 to a distribution line 64, which distribution line 64 is in turn connected to the upper end of the holding element 50 (which is opposite to the end at which the suction elements 17, 18 are provided).

From the upper end of the holding element 50, a hole or a duct extends inside the holding element 50 towards the suction elements 16, 17, so that vacuum can be applied to the suction elements 17, 18 by applying vacuum to the vacuum connection 60. The vacuum duct may also be configured to exhaust/blow air when the inserted sheet 11 is placed on top of the row of folded boxes 3 to release the vacuum and push the inserted sheet 11 away from the suction elements 17, 18.

As best shown in fig. 13 and 14, associated with at least one of the holding elements 50 is a sensing device 66, which sensing device 66 comprises a sensor 70 for detecting the displacement of the detection element 55 located on the respective holding element 50. The displacement is determined with respect to the support 20, 21 to which the holding element 50 is mounted. Accordingly, the sensor 70 may be configured to sense when the detection element 55 is in proximity to the sensor 70, and also configured to sense displacement as the detection element 55 moves further away from the sensor 70.

The sensor 70 may be a magnetic sensor or an inductive sensor. The sensor 70 is adapted to detect an upward displacement of the respective holding element 50 relative to the position shown in fig. 11. The detection element 55 may be located on the stop 54 and preferably comprises a material that can be detected by a magnetic or inductive sensor 70. For example, the material may be a metallic material.

As can be seen in fig. 14, the detection element 55 on the stopper 54 is arranged at the same vertical level as the sensor 70 and is opposite to the sensor 70 when the suction elements 17, 18 are not pressed against the inserted sheet 11 (in the loading position or against the row of folded boxes). Thus, when the clamping elements 17, 18 are in their lowest position (in which they are placed at the maximum distance from the respective support frame 80), the sensor 70 and the detection element 55 are aligned. As shown in fig. 13, the detection element 55 on the stopper 54 is arranged further away from the sensor 70 when the suction elements 17, 18 are pressed against the insertion sheet 11.

In the embodiment shown in fig. 10, the sensing device 66 includes a sensor 70 and a detection element 55. However, in the embodiment shown in fig. 13, the grasping system 15' includes a first sensor 70a and a second sensor 70b that read the first detecting element 55a and the second detecting element 55b, respectively. This is advantageous when the support frame 80 comprises a first frame part 80a and a second frame part 80b, wherein the first frame part 80a comprises a first set of clamping elements 17 and the second frame part 80b comprises a second set of clamping elements 18. The control unit 30 may be configured to receive signals from both sensors 70a, 70b and to be able to operate the clamping elements 17, 18 only when both sensor signals are received. Thus, the clamping elements 17, 18 can be operated when the two sensors 70a, 70b have determined the displacement of each respective detection element 55a, 55 b.

Preferably, the first sensor 70a and the first detection element 55a are located on the first frame portion 80a, and the second sensor 70b and the second detection element 55b are located on the second frame portion 80 b. In one embodiment, the first and second sensors 70a and 70b are disposed diagonally on the first and second frame portions 80a and 80b, respectively. In this way, when gripping the insertion sheet 11, the first sensor 70a and the second sensor 70b are diagonally arranged above the fold lines L1, L2, L3. This enables detection of whether the insert sheet 11 is not flat at its loading position 9 (for example, if the stack of insert sheets 11 is not flat). In this case, the gripping head 15 may be operated to activate the gripping elements 17, 18 when both the first detector 70a and the second detector 70b have sensed contact with the inserted sheet 11 (or storage position). Alternatively, a threshold distance may be applied to limit further downward movement after the first sensor 70a senses contact. The threshold distance is the vertical distance of the grasping head 15 after the first sensor 70a senses contact. For example, the threshold distance may be set to about 50mm. The threshold distance enables the gripping head 15 to be slowed and stopped. Alternatively, a threshold time duration may be used instead of the threshold distance. Similarly, the threshold time duration is set from when the first sensor 70a senses contact. The threshold distance or threshold time enables stopping grabbing the head 15 if the second sensor 70b does not sense contact.

Alternatively, a sensor 70 may be provided for each clamping element 17, 18. In the embodiment shown, four sensors 70 are provided.

As best shown in fig. 15, the gripping head 15 may operate linearly in the lateral direction L and the vertical direction V. The transverse direction L lies in a horizontal plane. The transverse direction L may be perpendicular to the transport direction T of the containers 2 at the location of the gripping head 15.

The first lowered position P11 of the gripping head 15 may be vertically aligned with the loading position P12 of the insertion sheet 11 located at the loading position 9. Similarly, the second lowered position P21 of the gripping head 15 is vertically aligned with the storage position P22. The storage position P22 is located in the container 2. The first lowering position P11 and the second lowering position P21 may be defined as coordinates in the memory 35 of the gripper system 15'. In one embodiment, the first descent position P11 and the second descent position P21 are defined only in the first lateral coordinate L1 and the second lateral coordinate L2 in the lateral direction L. The limited movement in the transverse direction L may be achieved by a linear guide 31 configured to guide the gripping head 15 in the transverse direction L.

Therefore, the first descent position P11 may be defined as one-dimensional spatial coordinates l1. Similarly, the second descent position P21 may be defined as one-dimensional spatial coordinates l2. These coordinates 11, l2 define the start (in the horizontal plane) of the vertical descent trajectories V1, V2 at the loading position 9 and the storage position 13, respectively. The first descent trajectory V1 at the loading position 9 extends between a first descent position P11 and a first vertical end position P12 (corresponding to the loading position). The second descent trajectory V2 at the storage position 13 extends between a second descent position P21 and a second vertical end position P22.

In another embodiment, no linear guide is present. In this embodiment, the lowered positions P11, P21 are defined in a two-dimensional horizontal plane defined by the longitudinal axis T and the lateral axis L. Coordinates (l 1, t 1) and (l 2, t 2) define the descent positions P11, P21.

The control unit 30 is configured to retrieve from the memory 35 the descent coordinates l1, l2 defining the descent positions P11, P21. The control unit 30 positions the gripping head 15 in the lowered positions P11, P21 and initiates the lowering of the gripping head 15 in the vertical direction V along the lowering trajectories V1, V2.

The first vertical end position P12 and the second vertical end position P22 may be defined only by the sensing device 66. Thus, when the sensing means 66 detects a displacement of the at least one detection element 55, a stop signal is generated by the control unit 30. Thus, when contact between the clamping elements 17, 18 and the surface is sensed. The surface may be a stack or a row of folded boxes into which the sheet 11 is inserted. Or when the plurality of sensors 70a, 70b sense the displacement of their respective sensing elements 55a, 55 b. In yet another embodiment, a stop signal is generated when one of the sensors senses displacement and a threshold distance or time has been exceeded.

Thus, the present sensing device 66 enables the gripping head 15 to sense the position of the inserted sheet 11 at the loading position 9 and also the storage surfaces 13, 14 at the storage position 13. The storage surfaces 13, 14 correspond to the top surface 13 of the row of folded boxes 3 and the bottom surface 14 of the container 2.

This is an important improvement, compared to the prior art WO2017/202500A1, in that a simpler system can be realized that is capable of automatically adapting to variable operating conditions. The previous system in WO2017/202500A1 requires more programming parameters, in particular when several layers of insert sheets 11 have to be stored at different heights in the container 2 (as shown in fig. 2 b). Thus, the control unit needs to retrieve predefined data for each vertical storage location. In reality, however, the vertical position at which the rows of folding boxes are actually positioned often differs slightly from the theoretical position. Thus, in order to mitigate the risk of damaging the box, the gripping head is decelerated before reaching the theoretical storage position, even if the speed loss is compromised. In contrast, in order to obtain an accurate system, the existing system requires a short setup time and simple programming of the coordinates of the descent positions P12, P21.

In addition to the advantages described above, the grasping system 15' of the invention also improves reliability and durability. Even if the sensed object is not inserted into the sheet 11 or the row of folding boxes 3, the gripping head 15 will automatically stop. For example, if an object is present in the descending trajectories V1, V2 of the gripping head 15, the control unit 30 will also activate the stopping of the gripping head 15 upon sensing contact with the object.

Another improvement to the system in WO2017/202500A1 is that the movable gripping elements 17, 18 are also configured to yield when contact with the inserted sheet 11 or the row of folding boxes has been detected. The stroke of the clamping elements 17, 18 may be selected such that the clamping elements 17, 18 are vertically movable after the sensing means 66 has detected contact. In this way, the gripping head 15 is still able to yield against the stack of inserted sheets or the row of folding boxes.

Alternatively, in one embodiment, a delay difference between the reception of the first sensor signal and the second sensor signal may be measured. If the difference exceeds a predefined threshold, control unit 30 may send an error signal to the central machine control system. Such a time difference between the sensor signals may indicate that the inserted sheet 11 is picked up or deposited on an uneven surface.

In another embodiment (not shown), the sensing means 66 comprises an electromechanical sensing switch comprising a mechanical latch configured to be activated at a predetermined displacement distance of the clamping elements 17, 18. The control unit 30 is configured to activate and deactivate the clamping elements 17, 18 in response to activation of the electromechanical switch.

In fig. 10 and 11, the gripping head 15 is shown in a state before being placed on the insertion sheet 11. The suction elements 17, 18 have their greatest distance from the respective support 21, 22, and the supports 21, 22 have the greatest horizontal distance from each other.

For gripping the inserted sheet 11, the gripping head 12 is moved vertically downwards until the suction elements 17, 18 contact the upper surface of the inserted sheet 11 in the stack arranged in the loading position 9. This process is best shown in fig. 1, the general principle of operation of which is also applicable to the present grasping system 15'. This contact stops the further downward movement of the suction elements 17, 18. When the holding element 50 is moved vertically relative to the support frame 80, the supports 21, 22 are moved further downwards, whereby the stop 54 is moved vertically upwards. This change in the position of the detection element 55 on the stop 54 relative to the supports 21, 22 can be detected by the sensor 70.

In response to a corresponding signal from the sensor 70, the control unit 30 prevents the drive means 16 from moving the gripping head 15 further downwards.

In an advantageous embodiment, the control unit 30 is configured to send instructions to the actuator 25, the actuator 25 gradually stopping/decelerating the downward movement of the gripping head 15 when the sensing means 66 detects a vertical displacement of the holding element 50 with respect to the support frame 80. The gradual deceleration provides a more controlled and softer contact between the suction elements 17, 18 and the insert sheet. The deceleration distance enables the suction elements 17, 18 to establish a vacuum connection. The biasing device 56 also enables the suction elements 17, 18 to yield when they contact the insert sheet 11, so that any undesired deformation of the insert sheet 11 can be avoided.

This state of the gripping head 15 is shown in fig. 12, it being seen that the biasing device 56 is in a compressed state, because the supports 21, 22 have been displaced down onto the holding element 50.

In this state, a vacuum generator (not shown) is connected to the suction elements 17, 18 and activated so that the respective insert sheet 11 is grasped by the suction elements 17, 18. Thereafter, the groups of suction elements 17, 18 can be moved toward each other in the horizontal direction H as shown in fig. 12 to reach the state shown in fig. 13, in which fig. 13 the insert sheet 11 is held with the fold (fold) 12. This is possible because the first and second frame portions 80a, 80b are horizontally movable relative to each other between a distal position in which the first and second sets of suction elements 17, 18 are positioned away from each other, and a proximal position in which the first and second sets of suction elements 17, 18 are positioned closer to each other (relative to the distal position).

In a subsequent step, the gripping head 15 is lifted upwards, so that the insert sheet 11 can also be lifted, as shown in fig. 14. This causes the biasing device 56 to return to its uncompressed state and moves the suction elements 17, 18 such that the suction elements 17, 18 return to a position in which they are placed at the maximum distance from the supports 21, 22.

The insert sheet 11 may then be transported to a location in the storage container where the insert sheet 11 should be stored. The control unit 30 determines when the gripping head 15 is in contact with the bottom of the storage container 2 or the top surface of a row of folding boxes 3 located in the storage container 2 based on information from the sensing means 66.

The control unit 30 then gradually stops/decelerates the downward movement of the gripping head 15, and releases the vacuum, so that the inserted sheet is stored. The suction elements 17, 18 may then be configured to actively release the inserted sheet 11 by exhausting/blowing air.

Preferably, as previously mentioned, the vacuum ducts in the suction elements 17, 18 are configured to expel air when the inserted sheet 11 is to be placed on top of the row of folding boxes 3 in order to release the vacuum and push the inserted sheet 11 away from the suction elements 17, 18.

Claims

1. A gripping system (15') for placing an insert sheet (11) between rows of folding boxes in a container (2), the gripping system comprising a gripping head (15), the gripping head (15) being configured to grip and pick up the insert sheet (11) from a loading position (9), to displace and position the insert sheet on a storage surface (13, 14) in the container (2),

The gripping head (15) has a support frame (80) and a plurality of gripping elements configured to adhere to an upper surface of the insertion sheet (11), the gripping elements being connected to the support frame by a plurality of holding elements (50), the plurality of holding elements (50) being movably mounted to the support frame, and wherein the holding elements and the gripping elements are movable in a vertical direction relative to the support frame when the gripping elements contact the storage surfaces (13, 14) in the insertion sheet or the container,

Wherein the gripping system further comprises a control unit (30) and a sensing device (66) configured to sense a vertical displacement of the holding element (50) relative to the support frame (80), and wherein the control unit is configured to receive information from the sensing device and to determine when the gripping head is in contact with an insertion sheet or a storage surface;

the gripping system further comprises a memory (35), the memory (35) comprising spatial coordinates (l 1) of a first lowered position (P11) and spatial coordinates (l 2) of a second lowered position (P21) of the gripping head (15),

The first (P11) and second (P21) lowered positions define starting points for a first (V1) and a second (V2) vertical lowering trajectory, wherein the first (V1) and second (V2) vertical lowering trajectory are vertically aligned with the loading position (9) and the second (V2) vertical lowering trajectory are vertically aligned with the storage surfaces (13, 14), and wherein the control unit (30) is configured to operate the gripping head to move into the first (P11) and second (P21) lowered positions, respectively.

2. The gripping system according to claim 1, wherein the control unit (30) is further configured to stop further vertical downward movement of the gripping head when the sensing means senses vertical movement of at least one of the holding elements.

3. Gripping system according to claim 1 or 2, wherein the storage surface (13, 14) is the upper surface of a row of folding boxes (3) or the bottom surface in the container (2).

4. Gripping system according to claim 1, wherein the holding element (50) is a rod received in an opening (52) in the support frame (80), and wherein the rod comprises a free end (53) on which the gripping element is attached.

5. The grasping system according to claim 1, wherein the gripping element is biased away from the support frame by a biasing member (56).

6. Gripping system according to claim 1, wherein the control unit (30) is configured to control the displacement of the gripping head and to operate the gripping elements in an alternating manner between a gripping state and a release state, such that the gripping elements are in a gripping state when the gripping head contacts the insertion sheet (11) in the loading position (9) and in a release state when the gripping head subsequently contacts the storage surface (13, 14) with the insertion sheet.

7. The gripping system according to claim 1, wherein the endpoints of the first vertical drop trajectory (V1) and the second vertical drop trajectory (V2) are defined by a first vertical end position (P12) and a second vertical end position (P22), and wherein the first vertical end position (P12) and the second vertical end position (P22) are defined only by the sensing device (66).

8. The gripping system according to claim 1 or 7, wherein the gripping system comprises a linear guide (31), and wherein the gripping head is linearly movable and guided by the linear guide in a lateral direction (L), and wherein the first lowered position (P11) and the second lowered position (P21) are defined as one-dimensional coordinates (11, L2) in a horizontal plane in a direction extending longitudinally of the linear guide (31).

9. The grasping system according to claim 1, wherein the sensing device comprises at least one sensor (70) located on the support frame and at least one detection element (55) located on at least one holding element (50), and wherein the sensor is configured to sense a displacement of the detection element.

10. The grasping system according to claim 9, wherein the sensor is a magnetic sensor or an inductive sensor, and the detection element includes a metallic material.

11. The gripping system according to claim 1, wherein the support frame comprises a first frame part (80 a) and a second frame part (80 b), the first frame part (80 a) comprising a first set of gripping elements (17) and the second frame part (80 b) comprising a second set of gripping elements (18),

And wherein the first and second frame portions are movable relative to each other between a distal position in which the first and second sets of clamping elements are positioned away from each other and a proximal position in which the clamping elements are positioned closer to each other than in the distal position such that the first and second sets of clamping elements (17, 18) are horizontally displaceable relative to each other.

12. The grasping system according to claim 1, wherein the gripping element is a suction element configured to apply suction to the insertion sheet.

13. The gripping system according to claim 9, wherein the control unit (30) is configured to apply a vacuum to the gripping head (15) when the sensor (70) detects a displacement of the holding element (50) relative to the support frame (80) and when the control unit determines that the gripping head is in the loading position (9).

14. The grasping system according to claim 1, wherein the grasping element is configured to vent air to apply positive pressure to the insertion sheet when the control unit determines that the grasping head is in contact with the storage surface.

15. Gripping system according to claim 1, wherein the control unit is configured to gradually stop/slow down the downward movement of the gripping head when the sensing means detects a vertical displacement of the holding element (50) with respect to the support frame (80).

16. A method of introducing an inserted sheet (11) into a container or between rows of folding boxes by using a gripper head comprising a plurality of gripping elements mounted to a vertically displaceable holding element (50) movably connected to a support frame (80) comprising a first frame part (80 a) and a second frame part (80 b), the method comprising the steps of:

Moving the gripping head (15) into vertical alignment with the loading position (9) and lowering said gripping head so that said gripping element contacts the upper surface of the inserted sheet,

Moving the support frame further downwards towards a predetermined distance, whereby the support frame moves relative to the holding element and the clamping element remains stationary against the upper surface of the insert sheet,

Detecting a displacement of at least one holding element and stopping a further downward movement of the gripping head,

-Moving the first frame part (80 a) towards the second frame part (80 b) such that the insert sheet is folded,

Picking up, displacing and positioning the insert sheet such that the insert sheet is aligned with an opening in the container,

Lowering the gripping head and placing the insert sheet on a storage surface (13, 14) in the container,

Moving the support frame further downwards towards a predetermined distance, whereby the support frame moves relative to the holding element and at the same time the insert sheet remains stationary against the upper surface of the insert sheet,

-Detecting a displacement of at least one holding element and stopping a further downward movement of the gripping head; and

-Releasing the gripping element from the insert sheet.

17. The method of claim 16, further comprising the step of:

-detecting a vertical displacement of the holding element with respect to the support frame with a sensor; and

-Stopping the vertical movement of the gripping head.